Infections of the nervous system are less frequent than infections of other systems such as the respiratory system, because the brain and spinal cord have no contact with the outside. Those infections that do occur gain entry through the bloodstream, the air spaces in the ears or sinuses, or through fractures caused by head injuries. Most nervous system infections cause obvious, serious illness. Early diagnosis is important, since prompt treatment can save a life and prevent long-term damage to the brain, the spinal cord or the nerves. You should familiarize yourself with the symptoms of this type of infection so that you can act quickly and decisively if anyone in your family gets one,